More and more excuses from your side. Example "Java iReport tutorial" will give as first hit iReport tutorial section. Do similar search for any other library you may like to use and I'm sure you will get plenty of resources.

you set up the layout of the report with the designer, set up the database connections, then their is some code you would put in a java class that when called would pass the params you want to crystal reports and crystal reports will generate a pdf or whatever with the data in the database using the parameters chosen.